<s>
The	O
KL-51	B-General_Concept
is	O
an	O
off-line	O
keyboard	O
encryption	O
system	O
that	O
read	O
and	O
punched	O
paper	O
tape	O
for	O
use	O
with	O
teleprinters	O
.	O
</s>
<s>
In	O
NATO	O
it	O
was	O
called	O
RACE	O
(	O
Rapid	B-General_Concept
Automatic	I-General_Concept
Cryptographic	I-General_Concept
Equipment	I-General_Concept
)	O
.	O
</s>
<s>
KL-51	B-General_Concept
is	O
a	O
very	O
robust	O
machine	O
made	O
to	O
military	O
specifications	O
.	O
</s>
<s>
As	O
of	O
2006	O
,	O
the	O
U.S.	O
Navy	O
was	O
developing	O
plans	O
to	O
replace	O
KL-51	B-General_Concept
units	O
still	O
in	O
use	O
with	O
a	O
unit	O
based	O
on	O
a	O
more	O
modern	O
Universal	O
Crypto	O
Device	O
.	O
</s>
